Sunan an-Nasa'i 4416
سنن النسائي#4416Sahihأَخْبَرَنَا أَحْمَدُ بْنُ نَاصِحٍ، قَالَ حَدَّثَنَا هُشَيْمٌ، عَنْ شُعْبَةَ، عَنْ قَتَادَةَ، قَالَ حَدَّثَنَا أَنَسُ بْنُ مَالِكٍ، قَالَ كَانَ رَسُولُ اللَّهِ صلى الله عليه وسلم يُضَحِّي بِكَبْشَيْنِ أَمْلَحَيْنِ أَقْرَنَيْنِ وَكَانَ يُسَمِّي وَيُكَبِّرُ وَلَقَدْ رَأَيْتُهُ يَذْبَحُهُمَا بِيَدِهِ وَاضِعًا رِجْلَهُ عَلَى صِفَاحِهِمَا .
Anas bin Malik said:"The Messenger of Allah used to sacrifice two pronounce the name of Allah and say: 'Allah Akabar,' and I saw him slaughtering them with his own hand, and placing his foot on their sides "(Sahih)
Scholarly Authentication
The label above is the grade most of these scholars gave — one dissenting opinion no longer speaks for all of them. If any scholar calls a narration fabricated, that verdict is shown instead, whatever the others say. Each scholar's own wording:
In-book reference: 43:56